Like daffodils, tulips are an iconic flowering spring bulb, filling gardens with color well before most other flowering plants have gained momentum. They are among the oldest cultivated plants and have been hybridized to produce just about every color except for true blue. The plants have two to six broad, strappy leaves with a waxy coat that gives them a blue-green color. Most tulips have one flower per stem, but a few are multi-flowering. There are literally thousands of different types of tulips spread over 15 official classifications based on flower shape, height, and time of bloom. The flowers are usually cup-shaped, with three petals and three sepals, but within this general description, there is a wide variety, including types with ruffled, fringed, and fully double blossoms that look more like peonies than tulips.
In most regions, tulip bulbs are generally planted in the fall, where they will then receive the winter chill required for them to bloom in the spring. Once they emerge from the ground, tulips grow and flower quickly. In cold-winter climates, they typically emerge in March and begin flowering in April to May, Although tulips are perennial bulbs, many hybrid types tend to be rather short-lived. Keeping a massive display of tulips requires planting additional bulbs each fall for the following spring's showcase.
Like other plants in the Liliaceae (lily) family, tulip bulbs contain alkaloid and glycoside compounds that are mildly toxic to humans and more seriously toxic to pets. In addition to causing gastrointestinal symptoms if the bulbs are consumed, tulip bulbs can cause a skin rash sometimes known as "tulip fingers" when handled.
|Botanical Name||Tulipa spp.|
|Plant Type||Perennial, bulb|
|Mature Size||9–24 in. tall, 6–9 in. wide|
|Soil Type||Rich, well-drained soil|
|Soil pH||Acidic, neutral|
|Flower Color||Red, Pink, Orange, Yellow, Green, Purple, Black, White|
|Hardiness Zones||3–8 (USDA)|
|Native Area||Europe, Asia|
|Toxicity||Toxic to humans, toxic to pets|
Tulips grow best as perennials in climates with moist, cool-to-cold winters and warm, dry summers. Plant the bulbs 4 to 8 inches deep in the fall (a depth about three times the size of the bulbs), in a sunny location with well-drained soil. Because they sprout and bloom so early in the spring, tulips can work well beneath trees and shrubs that will leaf out to create shady conditions later in the season. Space the bulbs 2 to 5 inches apart (depending on their size), with the pointy end facing up. Tulips tend to display best if planted in groups of about 10 bulbs.
Tulips are sometimes grown as annuals—especially the hybrid varieties. In this case, you can dig up and discard the bulbs after blooming is complete, then plant summer flowers in their place. Tulips are quite easy to grow for gardeners in cool/cold-winter regions, but hybrid types do need to be divided every few years to keep them from declining.
All varieties of tulips prefer full sun. Remember, though, that areas under deciduous trees that are shady in the summer are mostly sunny in the early spring when tulips are actively growing. Thus, these spaces can be excellent spaces to grow tulips and other spring bulbs.
Tulips prefer rich, well-draining soil with a pH that is neutral to slightly acidic (6.0 to 7.0). Mixing in compost can improve drainage and provide nutrients to the bulbs. Ideally, do this before planting the bulbs. Otherwise, you can apply a few inches of compost over the soil to encourage earthworms to tunnel into the soil, improving circulation and tilth.
Water the bulbs thoroughly immediately after you plant them, but withhold watering after this except during extended dry spells. If your region gets some rain every week or two, don't water your tulips at all. In arid regions, watering every two weeks is recommended.
Temperature and Humidity
Tulips thrive in regions with cool-to-cold winters and dry, warm summers—conditions found through much of USDA zones 3 to 8. They require 12 to 14 weeks of temperatures below 55 degrees Fahrenheit in order to bloom, so in regions with warm winter temperatures, they must be planted as annuals from suppliers who prechill the bulbs.
Tulips tend to do better in dry regions rather than humid climates since high humidity usually goes hand-in-hand with lots of spring and summer rain, which can cause bulbs to rot.
Add some compost, bone meal, or granular fertilizer to the planting hole when you plant the tulip bulbs. For the amount to use, follow the product label instructions. Feed them again the following spring, when they sprout again. Other than this, no additional feeding is necessary.
Types of Tulip
The variety of tulips available is somewhat bewildering since there are 15 separate divisions based on characteristics such as plant size, bloom time, flower shape, and genetic origin:
- Single early: Cup-shaped with one flower per short stem; first tulips to bloom, starting late March.
- Double early: More than the usual number of petals, with a fluffy appearance; tall stems (12 to 15 inches); start blooming in early April; can be harmed by cold snaps and winds.
- Triumph: Cross between early and late singles; tall stems (15 to 18 inches); late-April bloomers.
- Darwin hybrid: Cross between Darwin and Fosteriana; tall stems (24 inches) and very hardy; naturalize well; late-season, blooming into May.
- Single late: One bloom per stem; known for a wide range of colors and late-season bloomers.
- Lily-flowered: Tall (18 to 24 inches), late-season bloomers with pointed, slightly flared petals.
- Fringed: Fringed or ruffled petal edges in many colors, sometimes with contrasting colors on the fringe; late-season bloomers with 12- to 18-inch stems.
- Viridiflora: Late season blooms on 12- to 24-inch stems with distinctive green streaks in their petals.
- Rembrandt: Once prized for their colorful streaks and mottling; no longer grown commercially because the coloring was caused by a virus that spreads to other tulips; plants now advertised as 'Rembrandt' are cultivars that mimic the look of the originals.
- Parrot: Named for the bud's resemblance to a parrot's beak; flowers are large, with twisted, curling petals on tall stems (12 to 24 inches); late-season blooms.
- Double late: Also called peony tulips; tall stems (18 to 24 inches) with enough petals to rival a peony bloom; not particularly hardy but work well in containers.
- Kaufmanniana: Also known as the water lily tulip; early bloomers with wide-open flowers that are almost flat; leaves have brownish-purple mottling; short plants, only 6 to 12 inches tall.
- Fosteriana: Also known as emperor tulips; large flowers, often with pointed petals and available in many colors; bloom mid-season; plant 8 to 15 inches tall.
- Griegii: Short (8 to 12 inches), early-season bloomers with flared, pointed petals and wavy leaves; brightly colored, including some bi-colors.
- Species or wild tulips: Great for perennializing; short plants (4 to 12 inches) with lots of variety and varying bloom times.
There are literally hundreds of named cultivars across the various tulip divisions. A handful of the popular ones include:
- 'Purissima' (Fosteriana division): Very early, pale yellow petals that fade to white
- 'Ballarina' (Lily division): Fragrant with flared, pointed, orange petals
- 'Ballarina' (Fosteriana division): Sunny yellow with white tips that look like feathers
- 'Prinses Irene' (Triumph division): Rembrandt-style orange petals streaked with burgundy
- 'Spring green' (Viridiflora division): White petals with green center stripes; late-blooming and long-lasting
- 'Las Palmas' (Fringed division): Large, fringed white petals with a red flame, long-lasting cut flower.
- 'Vanilla Coupe' (Double late division): Yellow, double five-inch blooms with an outer layer of green petals, blooms in late May.
- 'Diamond Jubilee' (Triumph division): Mid-spring bloomer with creamy white petals edged in vivid pink.
When growing tulips as perennials, remove the flower stalks immediately after they flower to prevent the plants from producing seed pods, which drains the bulb's energy and shortens its life. Leave the foliage in place until it turns yellow in mid-to late summer. This helps replenish the bulb's energy.
While tulips can be propagated from seeds, the more common way to do it is by lifting the bulbs and dividing the offset bulbs (bulblets) that are attached to the mother bulb. This should be done in the fall, at the normal planting time for tulips.
- Dig up the bulbs with a trowel or spade, then brush off the soil and gently break off the small offset bulbs from the mother bulb.
- Inspect the offsets and discard any that appear soft or deformed.
- Replant the offsets and the mother bulb at a depth about three times the diameter of the bulb, with the pointed side facing up.
For the first few years, the new tulips may produce foliage but no flowers. At about the third year, you can expect the new bulbs to bloom.
How to Grow Tulips From Seed
Propagating tulips by seeds is not common, as they are very slow-growing, and seeds collected from hybrid plants generally do not "come true" to the original plant. Species tulips, however, will come true if you plant the seeds found in the pods left behind after the flowers fade. But nursing the seeds through germination to mature plants with bulbous roots is a slow process, requiring close to two years.
After collecting the seeds from the dried pods, store them in the refrigerator for at least 12 to 14 weeks, then sow them on the surface of small pots filled with potting mix. In cold winter zones, tulip seeds are often planted indoors in late February. Cover the seeds with a bare covering of additional potting mix (1/4 inch). Place the pots in a sunny location and keep them moist until the seeds sprout. The pots can be moved outside once the weather warms. Keep the seedlings growing in the pot through the spring, summer, and fall, feeding them weekly with a half-strength dose of balanced 10-10-10 fertilizer. This heavy feeding is necessary for the seedlings to create bulbous roots.
In late fall, move the potted plants back into the refrigerator—or into a cold frame for outdoor chilling. Again, the plants will need to be chilled for at least 12 weeks. In later winter or early spring after the chilling period is complete, bring the pots back outdoors to sprout and grow once more. Once the foliage is fully developed in this second growing season, the plants can be transplanted into their permanent garden locations. But remain patient, as it may take another full year before seed-started plants are ready to flower.
Potting and Repotting Tulips
Tulips are easy to grow in well-draining pots filled with standard potting mix. This is the method often used if you want to force tulips into midwinter bloom indoors, but timing is critical, as the bulbs require a 12- to 14-week chilling period. Plant the chilled bulbs about 2 to 3 inches deep, lightly moisten the soil, then store the pots in a dry, cool (35 to 55 degrees Fahrenheit) location for the recommended chill period. The pots can be chilled in a refrigerator, or outdoors in a sheltered location if you live in a cold-winter climate.
After the chill period, bring the pots into a bright room at moderately warm temperatures—about 60 to 65 degrees. Within three to five weeks, the plants should flower. Thus, for late January or early February bloom, the bulbs will need to be planted in late September and chilled until late December.
If growing them in cold-winter zones, garden tulips require no special winter protection, but it is best to withhold watering in fall, as wet winter soil can encourage bulb rot. Fall is a good time to divide bulbs, which is recommended every three to five years for hybrid varieties.
Common Pests and Plant Diseases
Tulip bulbs and foliage are popular with many animals, including deer, squirrels, and other rodents. In some areas, it's just not worth planting tulips in the ground, and you're better off growing them in protected containers. Alternatively, you can try deterrents or interplant the tulips with daffodils, but be prepared to lose a few.
Insect pests include:
- Aphids, which can be washed off with water spray or squashed with your fingers.
- Bulb mites, which sometimes are found in purchased bulbs. Inspect the bulbs for signs of decay. A brief two-minute soak in 120-degree water will kill mites.
- Thrips can be combatted with sticky traps, or by introducing ladybugs and green lacewings as predatory insects. Thrip damage may appear as brown or silvery streaks on the leaves of tulips.
Tulips are susceptible to basal rot and fire fungus. Basal rot appears as dark brown spotting or as pink or white fungus on the bulbs. Plants that grow from affected bulbs may be deformed and/or die early. The best remedy is to discard affected bulbs and plant new bulbs that have been treated with a fungicide.
Bulbs affected by fire fungi lead to malformed or stunted plants or plants that never emerge. Affected plants may have curling shoots or dead areas with dark green rings. Treat affected plants with a fungicide. Discard affected bulbs, and plant new bulbs that have been treated with a fungicide.
How to Get Tulips to Bloom
Mature tulip bulbs normally bloom reliably in the spring if the conditions are right—plenty of sun, and fertile, well-drained soil. When bulbs fail to bloom, it's usually for one of these reasons:
- The bulbs are not yet mature enough. Especially after dividing, small bulbs make take a year or two to develop into flowering plants. Good spring feeding will speed their development.
- The bulbs are too old. Hybrid tulips, in particular, are fairly short-lived. When your tulips begin to decline, dig them up and split off the younger offset bulbs to replant.
- The plants don't get enough sunlight. Tulips are sun-loving plants, so don't position them where fences, walls, or coniferous trees cast shade.
- The bulbs need feeding. Tulips are not heavy feeders, but you should give them a healthy dose of bulb fertilizer when planting and each spring thereafter.
Common Problems With Tulips
In the right location and climate, tulips are quite trouble-free, though hybrid types may decline much faster than you'd like—within three or four years. In addition, there are a few other common complaints;
Tall Varieties Flop Over
Some hybrid tulips have very large blossoms and flower stalks that can be 2 feet or more in height. These types may require staking, especially if the plants are in semi-shady locations, which encourages legginess.
Plants Collapse at Ground Level
When tulip stems grow soft and collapse at ground level, it's almost always due to root or stem rot caused by excessively moist soil. Remember that tulips are native to moderately dry regions of Europe and Asia, and will do best in conditions that mimic that environment.
Foliage Is Twisted, Distorted
This is usually a symptom of a serious fungal disease (see above) that will require you to dig up and destroy the bulb before it can spread to other plants.
Flowers and Flower Buds Are Streaked, Distorted
This is usually a symptom of tulip virus, for which there is no cure. Affected plants must be removed and discarded—not composted, which can allow the virus to be transmitted.
How do I use tulips in the landscape?
There aren't that many flowers in bloom when tulips put on their show, so they can be worked into any spot in the yard. They look best when planted in clusters, rather than lines. They make good companions for other spring bulbs, like Chionodoxa (Glory of the Snow), late daffodils, dwarf iris, and Scilla.
Some of the cool-season annuals, like snapdragons and pansies, provide a nice contrast to the bowl shape of tulip flowers. The blues of forget-me-nots and Virginia bluebells (Mertensia virginica) play up the bold colors of tulips.
Tulips also make great cut flowers. If a deer problem prohibits you from growing tulips in your yard, grow them in a fenced vegetable garden for cutting to enjoy indoors.
Can I grow tulips if I live in a warm-winter climate?
Because tulips require a chilling period, gardeners in warmer climates generally purchase pre-chilled bulbs and plant them afresh each year. In warm, Southern gardens, tulips can emerge in early January and bloom in early February. Make sure that you are buying prechilled bulbs if you plan to use tulips in this way. Or, you can also chill the bulbs yourself by giving them at least six weeks in a refrigerator at temps below 40 degrees Fahrenheit. But it is important not to store the bulbs in a refrigerator that is also being used to store fruits and vegetables, as produce outgases compounds that can prevent tulip bulbs from setting buds.
It is also possible for southern gardeners to dig up bulbs after the foliage has faded, then store the bulbs and chill them in the refrigerator before planting again in late fall. But bulbs dug up and reused this way do not have a very long life, and at most you'll get a couple of years of flowers from them. It is better to buy fresh chilled bulbs each year.
How long do tulip bulbs last?
The longevity of tulip bulbs varies considerably depending on the type you are growing. Species types are fairly long-lived perennials, returning and even multiplying year after year. But many hybrid forms will give you a good display for only two or three years, then begin to gradually decline.
How can I protect my tulips from squirrels?
Squirrels and other small rodents love to dig up and eat tulip bulbs–sometimes within hours of planting. One way to guard your bulbs is by burying chicken wire or hardware cloth over the bulbs. The metal wire will discourage rodents, but still allow plant shoots to emerge through the openings. There are also granular or liquid repellants you can use, though these will need to be applied every week or two until the plants have fully sprouted.
Finally, intermingling your tulip bulbs with bulbs that are repellant to squirrels can help. Rodents disdain hyacinths, alliums, and daffodils, for example, so mixing tulips among these bulbs may discourage these creatures.